So in February 2020, I came down with what I thought at the time was food poisoning. I started feeling queasy before lunch and finally left work after projectile vomiting in my wastebasket, and had to be walked downstairs to hail a cab home. I spent the next 36 or so hours in bed, where I had uncontrollable chills and sweats, in spite of being bundled in flannel pajamas, a fleece robe, and a giant down comforter in a warm house. By the evening of day 2, I was almost back to normal, if somewhat weak.
Then The Plague hit the U.S. in force shortly thereafter. I got vaccinated as soon as I could, and am now fully vaxxed and double-boosted. And chances are that in fact, I had food poisoning or something back then. But part of me still wants to know whether I already had COVID, because it would take a load off my high-risk mind if I knew that I’d already had it and emerged relatively unscathed. (And hey, if my then 79-year-old asthmatic father had an asymptomatic case at the same time that my much younger, non-asthmatic stepmother had the case that killed her after a month in the ICU on a ventilator, anything is possible.)
My GP says there’s no real way to know, because I will have vaccine-produced antibodies anyway, but maybe he doesn’t know everything? He’s a very solid GP, but he’s not a virology expert.
You are American I believe.
There are roughly two types of Covid antibodies which can be detected in a test. S (spike) and N (nucleocapsid). The vaccines in the US cause only produce “S”. So theoretically if you have “N” antobodies, that is a sign of prior infection.
But of course, how reliable it is, is something only a professional can give you.
As AK84 says, there are tests that can differentiate them.
Reasoning from basic statistics, it’s extremely unlikely that you had Covid in Feb 2020. There were a few cases in the US at that time, but really very few compared to the number of people who get sick in a random Feb. Back of the envelope if people get sick with some minor illness (cold, food poisoning, whatever) ~2x a year and there are 330 million Americans, then 50+ million people had some kind of ailment in Feb and, like, maybe a few hundred or a few thousand of those were Covid cases. Combine that with the fact that “projectile vomiting” is not a common covid symptom, and we’re rapidly approaching “winning the lottery” levels of probability that that sickness you had was Covid.
On the other hand, unless you were getting tested regularly, there’s a decent (not super likely, but much more likely than the above) that you’ve had a totally asymptomatic infection sometime in the last 2 years when Covid was prevalent. So an antibody test could show you that.